Dual pattern controlled machine tool



Oct 1943- E. G. ROEHM 2,332,532

" I DUAL PATTERN CONTROLLED MACHINE TOOL Filed 001' 3, 194 5Sheets-Sheet 2 V a; 2M M d1 q .96

E, f 2 215 ff H2176 %fi10 ,5? n

I17 INVENTOR. I [iM/Y/PQ///7 ATTORNEY.

1943- E. G. ROEHM 2,332,532

DUAL PATTERN coNTRbLLED MACHINE T601.

Filed Oct. 3, 1940 5 Sheets-Sheet 4 177 1a! m M5 5 Q Ma 16'5" I IINVENTOR.

BY fad/116 Paw/*1 ATTORNEY.

Oct. 26, 1943. E.- G. ROEHM I 2,332,532

DUAL PATTERN CONTROLLED MACHINE TOOL Filed Oct. 3, 1940 s Sheets-Sheet sINV ENT OR. few/v6. Poi/7m ATTORNEY.

Patented Oct. 26, 1943 UNITED STATES PATENT OFFICE Erwin G. Roehm,Norwood, Ohio, assignor to The Cincinnati Milling Machine (30.,.Cinclnnatl, Ohio, a corporation of Ohio Application October 3, 1940.Serial No. 359,579

21 Claims.

This invention relates to pattern controlled machine tools such asmilling machines and the like.

One of the objects of this invention is to provide a new and improvedduplex pattern controlled milling machine.

Another object of this invention is to provide in a die-sinking machineimproved and simplified means for obtaining simultaneousthreedirectional control of relative movement between a cutter and workpiece whereby automatic control of depth may be obtained during anydirection of feed.

A further object of this invention is to provide a new and improvedtracer control mechanism for a pattern controlled machine tool.

An additional object of this invention is to provide improved means forincreasing the rate of relative movement between the cutter and workwithout interfering with the tracer action.

Other objects and advantages of the present invention should be readilyapparent by reference to the following specification, considered inconjunction with the accompanying drawings forming a part thereof and itis to be understood that any modifications may be made in the exactstructural details there shown and described, within the scope of theappended claims, without departing from or exceeding the spirit of theinvention.

Referring to the drawings in which like reference numerals indicate likeor similar parts:

Figure 1 is a view in elevation of a machine embodying the principles ofthis invention.

Figure 2 is a plan view of the duplex patterns as viewed on the line 2-2of Figure 1.

Figure 3 is an enlarged section through the feed directional controltracer as viewed on the line 3-3 of Figure 1.

Figure 4 is a detail section on the line 4-4 of Figure 3.

Figure 5 is a detail section on the line 5-5 of Figure 3.

Figure 6 is a view in elevation of the rapid traverse control lever asviewed on the line 6-6 of Figure 5.

Figure '7 is an elevational view partly in section of the elevatingcontrol mechanism.

Figure 8 is an enlarged section through the vertical tracer control, asviewed on the line 8-8 of Figure 1.

Figure 9 is a detail section on the line 3-9 of Figure 7..

Figure 10 is a section on the line l8l0 of Figure 3.

Figure 11 is a section on the line ll-ll of Figure 3.

Figure 12 is a diagrammatic view of the by draulic control circuit.

Referring to Figure 1 of the drawings the reference numeral l0 indicatesthe bed of a machine embodying the principles of this invention. A tableII is supported by suitable guideways for reciprocation upon the top ofthe bed and this movement may be effected by a hydraulic motor of thepiston and cylinder type which, as shown in Figure 12, comprises acylinder l2, a piston l3 and a piston rod H, the latter serving toconnect the piston l3 to one end of the table II.

A column l5 uprises from the rear of the bed and is provided with spacedguideways l6 upon which reciprocates a cross slide or carrier ll. Thiscross slide is adapted to be actuated by a hydraulic motor of the pistonand cylinder type which, as shown in Figure 12, comprises 9. cylinderl8, a piston I 9 and a piston rod 28, the piston rod serving to connectthe piston I3 to the column i5 whereby the cylinder is the movingelement. The cross slide is provided with vertical guideways 2| forreceiving a. vertically movable carrier 22. This carrier is alsoactuated by a hydraulic motor of the piston and cylinder type which, asshown in Figure 12, comprises the cylinder 23, piston 24, and the pistonrod connecting the piston to the carrier I'I whereby the cylinder is themoving element.

Hydraulic actuation of the table piston I3 is controlled by a reversingvalve 26, which has two ports 21 and 28 connected by channels 29 and 30to the respective ends of the cylinder l2. This valve also has apressure port 3| which is supplied-by a pump 32 from reservoir 33through channel 34. The exhaust ports 35 and 36 of this valve areconnected by a channel 31 to the reser voir 33.

A 'shiftable plunger 38 having a central spool 33, and annular grooves40 and 4t on opposite sides thereof, serve to alternately connect thepressure port 3| to ports 21 or 28, and connect the remaining port toone of the exhaust ports to effect reversible movement of the table.Hy-- draulic actuation of the cross slide is controlled by a secondreversing valve 42 which has a pair of ports 43 and 44 which areconnected by channels 45 and 46 to opposite ends of the cylinder l8.This valve also has a pressure port 41 which is supplied from channel 34and a pair of exhaust ports 48 and 49 which are connected to the returnchannel 31.

A shiftable plunger, having spaced annular grooves 5| and 52, serves toconnect the pressure port 41 alternately to the ports 88 and 48, whileconnecting the remaining port to one of the exhaust ports 48, 48.

The valves 28 and 82 are mounted in the tracer housing 58 and at rightangles to one another and parallel to the axis of movement of therespective slides which they control. The plungers of these valves areconnected to a. tracer in such manner that deflection of the tracer inany given direction radially to the axis thereof will cause relativemovement between the cutter andwork in that direction.

The cutter 58 is attached to a vertical spindle 55 which is rotatablyjournaled in the vertical slide 22, suitable means not shown beingprovided for power rotating the spindle. Since the vertical slide 22 iscarried by the cross slide H, the tracer housing 58 which is mounted onthe vertical slide 22 is responsive to movements of both of theseslides. I

The vertical slide has a laterally projecting bracket 55 upon which isformed a guideway 51 extending parallel to the direction of cross slidemovement. A sub-support 58 is mounted on the guideway 51,'and in turnsupports a vertically movable slide 58 which constitutes a carrier forthe tracer housing 88. The slide 58 has a horizontal guide 58 integrallyformed therewith and the tracer housing 58 is adjustably mounted on thisguideway. By means of this combination of parts it is possible to effectthree directional adjustment of the tracer housing relative to thecutter 54 for initial set-up purposes.

The manner of connecting the valve plungers 88 and 58 to the tracer ismore particularly shown in Figures 3 and 4. Referring to Figure 3, apendulum tracer 6| is supported at its upper end within the tracerhousing 58 by means of a flexible diaphragm 82 which has its outer rimclamped between members 88 and 64 by screws 85.

The member 84 also provides an annular surface 86 which engages theunderside of the diaphragm adjacent to the periphery of the tracer. Theupper end of the tracer is reduced to form a shoulder 81 and a reducedthreaded shank 68 which passes through a central hole in the diaphragmso that the diaphragm engages the shoulder 81. A threaded nut 88 andwasher 18 serve to clamp the center portion of the diaphragm to thetracer. The diaphragm has suflicient flexibility so that the tracer maybe deflected laterally at its lower end while the annular surface 85holds the tracer against downward axial movement but does not preventupward movement.

The tracer has a cylindrical portion 1| upon which is mounted a sleeve12 having an enlarged end 18 upon which is formed an external taperedsurface H. A spring is interposed between the enlarged end of the sleeveand a shoulder 15 formed on the tracer for exerting a continuous axialurge on the sleeve in a direction to force the tapered surface 14 intothe bore 11 of an annular ring 18. This ring is attached to the insideof the tracer housing with the bore 11 in concentric relation to thenormal position of the tracer axis when freely suspended by thediaphragm whereby the pressure on the sleeve acts to centralize thetracer. When the tracer is thus centralized the two valve plungers arecentralized in a stop position and connected to the tracer so that nomovement of either the table or cross slide will occur while the traceris centralized.

The sleeve 12 carries an annular rlng 'l8 and around this ring arepositioned two Scotch yokes 88 and 8 I. As shown in Figure 4, the Scotchyoke 88 has two upstanding integral ears 8| and 82 which are providedwith flat faces 83 for enga ing opposite sides of the ring 18. TheScotch yoke 8| has two integral downwardly projecting ears 8 and 85which are also provided with flat faces 88 for engaging opposite sidesof the ring 18. It will be noted that the ears on one yoke are spaced180 degrees apart and also 90 .degrees apart with respect to the ears onthe other yoke. The valve plunger 58 is connected to the upstanding ear8| by means of a threaded connection 86 to an insert 81 counterseated inthe face 83. The same type of connection is provided for connecting theplunger 88 to the downwardly extending ear 84.

Since there is no lost motion in these connections it will be apparentthat lateral movement of the tracer in any direction will produce acomponent or components of movement of the two valve plungers and causea shifting thereof in a direction that will cause power movement of oneor both slides.

In order to insure that the slides do not creep due to any slightleakage in the valves, means are provided which will produce a counteror opposing movement that will effect a sufliclent minute shifting ofthe valve plunger in the proper direction to stop the movement. In otherwords, each plunger is provided with a pair of fluid operable pistonslocated adjacent opposite ends of the plunger. As shown in Figure 12,the plunger 88 is provided with centralizing pistons 88 and 88,

the cylinder 88, containing piston 88, being connected by conduit 8! tochannel 88, and the cylinder 82, containing piston 88, being connectedby conduit 83 to channel 28.

Thus, should the pressure rise in channel 38 above the pressure inchannel 28 due to the spool 88 of valve plunger 38 being slightly to theleft as viewed in Figure 12, this slight increase in pressure would becommunicated to the centralizing piston 88 and being slightly greaterthan the pressure communicated to piston 88 through branch 88 fromchannel 28 a slight movement would be imparted to the plunger toward theright until the pressures in both channels 28 and 88 are equalized. Whenthis occurs the pressures on the centralizing pistons 88 and 88 would beequalized and further shifting of the valve plunger 88 would cease.

The valve plunger 58 is also provided with a pair of centralizingpistons 84 and 85 which are slidable in cylinders 86 and 81 respectivelyand connected by channels 88 and 88 to channels 85 and. Thus, if theplunger 58 shifts off center, the pressure would rise in channel 45 andcause the piston 84 to urge the valve plunger 58 back to acentralposition. Should the pressure rise in channel 46, the piston 85 wouldurge the plunger back to a central position.

A feed adjusting nut I88 is threaded on the tracer as shown in Figure 3for engagement with the lower end of the sleeve 12. By rotating the nutI88 the sleeve can be shifted axially to effect a predeterminedclearance between the taper I3 and the centralizing ring 18, and theamount'of this clearance determines the amount that the control valvesmay be shifted from a central position and thereby the rate of feed thatwill be imparted to the connected slides.

In addition to the feed control, the tracer also carries means forimparting a rapid traverse movement to the slides without disturbing thesetting of the feed control. This is accomplished by mounting on thesleeve 12 a support IOI which has a tubular portion I02 by which it isfitted to the sleeve. A U-shaped rapid traverse control lever I03 whichis more particularly shown in Figures 5 and 6 is pivotally connected tothe support IN by a pin I04. The lever I03 is provided with a pair ofdownward extending knife edges I05 which engage the top surface of thefeed nut I at diametrically opposite points. The lever I03 has a handleI08 as shown in Figure 8 for rocking the lever about the knife edges aspivots whereby the opposite end of the lever is elevated to raise thesupport IN and thereby the sleeve 12 to which it is attached, increasingthe clearance between the taper 13 and the cen-- tralizing ring 18,whereby the valves may be moved a greater distance from their centerposition to increase the rate of movement of the connected slides.

It should now be evident that the operator by means of the hand grip I01may deflect the tracer laterally in any direction to produce a cuttingpath in that direction. When following apattern the operator maintainsan urge in a direction at 45 degrees to the face of the pattern toproduce two components, one of which is perpendicular to the fact of thepattern whereby a continuous urge is present to maintain the tracer incontact with the pattern and thus sensitive to undulations thereinduring the feeding movement.

The maintaining of this urge by the operator is rather tiresome andtherefore mechanical means have been provided by this invention forproducing such an urge. referring to Figure 3 a depending bracket I 08is attached to the underside of the tracer housing and the lower end ofthis bracket is provided with a bore I09, which is concentric to thenormal axis of the tracer. A tracer deflecting plunger H0 is mounted ina carrier III which is Journaled for rotation in the bore I09. A topplate II2, attached to the carrier by screws II3, serves to hold thecarrier in the bore.

The plunger has an enlarged head II4 which is adapted to engage the sideof the tracer and a spring H is interposed between the end of this headand the end of a bore H6 in which the plunger slides to exert thedeflecting urge on the tracer. The end of the plunger is provided with aknob II1 by which the plunger may be retracted from engagement with thetracer and so rotated that a cross pin II8 located in the plunger mayengage the exterior of the carrier and thus hold the plunger in aretracted position.

The tracer thus becomes free for manual manipulation. It will be obviousthat by supporting the carrier III for rotation in the bracket I08, thatthe carrier may be rotated to change the direction of deflecting urge onthe tracer. The amount of this rotation is, however, limited to 90degrees by means of a stop block II9, Figure 11, which is attached tothe carrier and rides in an arcuate groove located on the underside ofan indexible ring I20 which determines the orientation of the arc ofrotation of the plunger carrier. The indexible ring is provided with alocking pin I2I, Figure 10, which is adapted to be inserted in any oneof four equally spaced holes I22 formed in the periphery of the lowerend of the bracket I08. Thus, the ring may be locked in any one of fourdifferent positions to limit the arcuate movement of the plunger carrierto any one oi four quadrants.

The purpose of limiting the movement of the plunger carrier to degreesis that at any time during a feeding movement the carrier may be rotatedthrough an angle of 90 degrees, which will immediately change thedirection of deflection of the tracer sufficiently to reverse thedirection of feeding movement of the cutter.

As an example of how this deflector might be utilized, there is shown inFigure 2 a pattern carrier I23, upon which is mounted a pattern I24having a cavity I25 formed therein. A sine bar I26 is superimposed overthis cavity and the tracer BI is adjusted in such position that it mayengage'the sine bar. By applying a directional urge by the plunger H4 inthe direction of the arrow I21, the tracer will be urged in thedirection of component I28 toward the face of the sine bar, as well asin the direction of a second component I29 whereby a feeding movementbetween the cutter and work will take place parallel to the direction ofthe arrow I29.

When the tracer reaches one end of the 'cavity, such as the wall I30thereof, the operator rotates the carrier III through an angle of 90degrees and thereby sets up a new directional urge in the direction ofarrow I3I which will now produce a feeding movement in the oppositedirection with respect to the arrow I29. The sine bar is supported forsliding movement on a supporting bar I32 and a lead screw I33 isthreaded into the support I34 of the sine bar whereby rotation of thescrew will effect a lateral shifting of the sine bar. Thus, by rotatingthe crew a predetermined amount simultaneously with rotation of theplunger carrier, the feeding direction of the cutter may not only bereversed but relatively shifted to create a new cutting path.

The tracer and cutter are carried by the vertical slide 22 which ismoved hydraulically by the admittance of fluid pressure to one end orthe other of cylinder 23. Two different means are provided forcontrolling this admittance of pressure, one of which is a manuallycontrolled servovalve I35, and the other, a tracer controlled valve I36.A selector valve I31 has a shiftable plunger I38, which determines themethod of control.

The plunger I38 has an axial bore I39 in which is mounted a plunger I40and a spring I, the spring acting to normally position the valve plungerI38 in its right hand position. In this position the channel I42 fromone end of cylinder 23 would be connected through port I43,'an-

:- nular groove I44 of valve plunger I38 and port I45 to channel I46which leads to port I41 of the.

servo-valve I35. Channel I48 from the other end of cylinder 23 would beconnected through port I49, annular groove I50 of valve plunger I38 andport I5I to channel I52 which leads to port I 53 of the servo-valve I35.

The ports I41 and I53 of the servo-valve are located on opposite sidesof a pressure port I54 which is directly connected to the pump 32. The

. servo-valve also has a pair of ports I55 and I50 located at oppositeends of the valve which are connected to a return line I51 which leadsto the reservoir 33. The plunger I58 of this valve has a central spool I59 which normally closes the pressure port I54 and a pair of annulargrooves I60 and "SI located on opposite sides thereof and of suchdimension that when the central spool I59 closes the pressure port, thetwo exhaust ports I55 and I56 are also closed whereby there is no flowto the cylinder 23. A slight relative movement, however, of the plungerIII in either direction will cause fluid to flow from the pump to oneend of the cylinder 22, as well as flow from the other end of thecylinder to the return line.

The manual control means for the servo-valve are more particularly shownin Figure "I. It will be noted in this figure that the plunger I" isintegrally connected to a servo-screw III which, in turn, is operativelyengaged by a threaded half-nut "2. The halt-nut is pivotally connectedto a bracket I82. Figure 9, by a pin I" whereby the half-nut may beoscillated into or out of engagement with the servo-screw. The bracketI" is mounted on the rear face of a vertical plate I I which is attachedat its upper end to the cross slide I1 whereby the plate I ll is fixedagainst vertical movement. It will be noted from Figure 7 that the valvehousing I" is mounted in the vertical slide 22 and therefore is subjectto vertical movement.

The servo-screw Iti' has a reduced lower end I" which fits in a splinehole Ill formed in a rotor I" which is supported by anti-frictionbearings III in the slide 22. A spring I10 is also mounted within therotor for exerting an axial thrust on the servo-screw to take up lostmotion between the parts. The rotor I" is provided with bevel gear teethIll which intermesh with a bevel gear I12 mounted on a shaft Ill.

The hand wheel I14, attached to the outer end of shaft I12, serves asmeans for imparting manual rotation to the servo-screw Iii. It shouldnow be evident that with the nut H2 fixed in place that rotation of thehand wheel Ill will cause axial movement of the servo-screw Iii, therebydisplacing th valve plunger I58 axially to open the various ports in theservo-valve. This will result in a relative movement between the piston24 and the cylinder 22 whereby the slide 22 and valve housing I 25, aswell as theactuating mechanism for rotating the screw will be movedaxially relative to the screw. Movement of the valve housing will closethe pressure port and exhaust ports, thereby stopping the movement.Thus, the movement of the vertical slide will continue in eitherdirection only so long as the hand wheel I14 is rotated, and as soon asrotation stops the servo-valve restores itself and thereby stops theslide.

The tracer valve I36, Figure 8, is provided with a tracer Ill which isadapted to engage a pattern I18 which may be suitably positioned on thetable as shown in Figure 1 and 2. The pattern is provided with asuitably formed surface for automatically controlling the verticalmovement of the vertical slide independently of the movements elected bythe tracer 6i and regardless of the direction of those movements wherebysimultaneous three-dimensional control of the cutter may be obtained. V

One form of tracer valve mechanism for controlling the vertical movementautomatically is shown in Figure 8 of the drawings. The tracer Ill issupported in the housing I by a ball and socket bearing Ill! whichpermits universal lateral movement of the tracer. The upper end of thetracer armis provided with a conical socket ill in which is mounted aball ill, the ball being interposed between the conical socket andspherical bearing Ill formed on the lower end of a sleeve I" which isthreaded in the end of the tubular valve member III. A spring "2 exertsa continuous axial pressure on the valve member to seat the ball I18 andseat the tracer on its ball and socket bearing I16. It will be obviousnow that any lateral movement 0! the tracer will tend to cause the ballto lift and thereby eirect an upward axial movement of the valve sleeve.

Referring to Figure 12, the tracer valve III ts provided with a pressureport III, a pair of motor ports I" and Ill and apair of exhaust ports I"and Ill. The valve plunger III is provided with a central spool Ill anda pair of annular grooves I ll and I" on opposite sides thereof. Thvalve plunger is shown in Figure 8 in its lowest position, in which thespool Ill is displaced downward a sufficient amount to connect thepressure port I 82 to the motor port I. Fluid pressure will. therefore,flow through the channel Isl to port I" of the selector valve I21. Theport "2 is connected at all times by the annular groove in to the radialport Ill in plunger I" which intercommunicates with axial bore III. Thisapplies hydraulic pressure, in addition to the spring pressure, tomaintain the selector valve plunger I 38 in its right hand position.-

As the tracer valve III moves upward it tends to reduce the pressuredifferential between channel III and channel Ill which connects thepressure port I" to port I" located in the right hand end of theselector valve housing I21.

It will be noted that the end area of the valve plunger I38 is muchlarger than the end area of the plunger I". Therefore, as the tracervalve spool I moves toward a central position with respect to port I"but before it reaches that position a suilicient change in the unitpressures in channels Ill and Ill will be eflected whereby the valveplunger Ill will be shifted into the position shown in Figure 12,thereby connecting port I92 to port I, and port I26 to port I. This willdisconnect the manual servo-mechanism from control of the verticalcylinder and effect connection of the latter for control by the tracervalve.

In addition, these respective pressures will be immediately communicatedto the ends of piston 24 through channels I42 and I which are nowconnected through the selector valve to channels Iiiand ISIrespectively. It should be noted that the unit pressure in channel I isstill lower than the unit pressure in channel Ill but the lower unitpressure multiplied by the larger area of the lower end of piston 2 willbe greater than the higher unit pressure multiplied by the smaller areaof the upper side of piston 24, thus producing a downward resultantwhich will cause downward movement of the cutter slide 22.

Thus, the operator establishes contact of the tracer with the pattern bymeans of the manual servo-control and when this contact has been madeand the tracer deflected to eflect shifting of the selector valve thecontrol of the vertical slide 22 is automatically taken away from theoperator and assumed by the tracer. At the same time, in order toprotect the servo-mechanism, means have been provided for automaticallydisconnecting the half-nut I62 from the servo-screw ll i so thatcontinued rotation of the screw will produce no eflect.

This automatic disconnection is accomplished by providing the selectorvalve with a pressure port I91 which is supplied from the pump channelit and this port is connected when the selector valve is shifted to theleft to port I whereby the pressure fluid will flow through channel I89and ball check valve 2" to cylinder 2II containing piston 2'2. Actuationof the piston will rotate the half-nut I52 out of engagement with theservo-screw, as shown in Figure 9, against the pressure of spring 203which will be further compressed upon actuation of the piston. When theselector valve returns to its normal position the port I98 is connectedto an exhaust port 200 but the check valve 200 will prevent the fluid incylinder 2'0l from escaping through this path. A resistance coil 205 is,therefore, connected through branch 200 to the portion 201 of thechannel between the check valve 200 and the cylinder 20l The spring 203,therefore, acts to force the piston 202 backwards, compressing the fluidand forcing it through the resistance 205.

After the tracer has assumed control and the automatic downward movementof the vertical slide 22 starts the movement will continue until thetracer has been deflected sufliciently to create equal resultantpressures in both ends of cylinder 23. Equilibrium will then beestablished and the slide will stop.

The tracer is now in a condition to be responsive to variations in thecontour of its associated pattern, whereby eminences on the pattern willproduce an upward movement and depressions in the pattern will produce adownward movement.

Since the operator, due to focusing his attention on the vertical tracerwhile adjusting the vertical slide, might effect collision of the othertracer 6| with some object, safety means have been provided wherebyabnormal end pressure on the tracer 6| will cause automaticdisengagement of the half-nut I62 from the servo-screw. This meanscomprises a valve plunger 208 which is slidably mounted in the upper endof the tracer housing 53 and held in engagement with the upper end ofthe tracer 6| by a spring 209. As shown in Figure 12, this plunger hasan annular groove 2 I which controls the connection between a pressureport 2 and port 2| 2. The valve is normally in a position that theseports are disconnected but when the plunger is shifted upward tointerconnect these ports the pressure fluid will flow through branchline M3 to channels 206 and 201 and thereby to cylinder 20!.

The resistance coil 205 will block the escape of fluid to the returnchannel 31 sufliciently to cause actuation of the piston 202 and thecheck valve 200 will prevent escape of fluid through the exhaust port204 should the selector valve be in a right hand position. It should nowbe evident that means have been provided in association with each tracerand independently operable by the respective tracers to render themanual control means ineflective upon a predetermined amount ofdeflection of either tracer.

There has thus been provided an improved dual tracer control contouringmachine which by the use of dual patterns properly contoured willcontrol simultaneously three-directional relative movement between acutter and work piece.

What is claimed is:

1. In a contouring machine having a pair of supports, one of which isadapted to carry a work piece, means for mounting said supports formovement in horizontal planes, and a tool support carried by one of saidpairs of supports for movement perpendicular to said planes, thecombination of power operable means for effecting relative movementbetween said supports in a horizontal plane, additional power operablemeans for effecting movement of the tool support, and control means forsaid power operable means including a first tracer for determining thedirection of relative movement between the work support and tool supportin a horizontal plane, and a second tracer for controlling the directionof relative movement between the work support and tool support in avertical plane.

2. In a contouring machine having a tool support and a work support, thecombination of power operable means for effecting relative movementbetween the supports in a given plane, power operable means foreffecting relative movement between the supports perpendicular to saidplane, means for governing the respective power operable means includinga first tracer for controlling the direction of movement in the givenplane, and a second tracer for controlling the direction of relativemovement perpendicular to said plane. v

3. In a contouring machine having a tool support, a work support andmeans on one of said supports for mounting a pair of patterns, one ofwhich is outlined to determine the contour in a horizontal plane and theother of which is outlined to determine the contour in a vertical plane,the combination of power operable means for effecting relative movementbetween the supports in a horizontal plane, power operabl means foreffecting relative movement between the supports in a vertical plane, apair of tracers mounted on one of said supports for cooperating with thepatterns carried by the other support, said tracers being supported inparallel relation to the tool axis, means controlled by one of saidtracers for governing operation of the first-named power operable means,and means controlled by the other tracer for governing operation of thesecond-named power operable means.

4. In a pattern controlled machine tool, the combination with a worksupport and a tool support, one of said supports being equipped with atracer and the other being equipped with means to hold a pattern incooperative relation to the tracer, of fluid operable means foreffecting relative movement between the supports in one plane, meanscontrolled by the tracer for governing said movement, means to guide oneof said supports for movement perpendicular to the said plane, fluidoperable means for governing said last-named movement and an additionaltracer and pattern for controlling operation of said lastnamed fluidoperable means.

5. In a pattern controlled milling machine, the combination with a toolsupport and a work support, of fluid operable means for effectingrelative movement between the supports in one plane, a tracer mounted onone of said supports and adapted to cooperate with a pattern mounted onthe other support, means controlled by the tracer for determining theresultant direction of relative movement between the supports,additional fluid operable means for effecting relative movement betweenthe supports perpendicular to said plane, a second tracer carried by oneof said supports for cooperation with a second pattern carried by theother support, and means controlled by the second tracer for governingoperation of said additional fluid operable means concurrently duringrelative movement between the supports in said plane.

6. In a pattern controlled milling machine having a work support and atool support, the combination of a fluid'operable'motor for effectingrelative movement between the supports, a tracer, a tracer controlledvalve, control channels connecting said valve to said motor, and meansconnecting said channels to opposite ends of said valve whereby unequalpressures in said channels will react to centralize the valve andprevent inadvertent creeping of the slide when the tracer is free.

7. In a contouring machine, the combination of a work support, a toolsupport, manually operable means for feeding one or said supports towardand from the other support, a pair of tracers carried by one of saidsupports for engaging separate patterns carried by the other support,fluid operable means for rendering said manually operable meansineffective, and means in each tracer responsive to deflection thereoffor connecting a source or fluid pressure to said fluid operable means.

8. In a milling machine having a work support and a tool support, thecombination with fluid operable means for effecting relative movementbetween the supports, of a valve, a tracer pivotally attached at one endof one said supports for lateral deflection to shift the valve andcontrol the flow oi fluid pressure to said fluid operable means, meanssurrounding the tracer for controlling the amount of deflection thereofand thus the rate 01' said relative movement including a sleeve mountedon said tracer and having a tapered portion, the tracer support having abore formed therein, means to force the tapered portion of the sleeveinto said bore for centralizing the tracer, and means to adjust thesleeve to control the amount of tracer deflection.

9. In a milling machine having a work support and a tool support, thecombination with fluid operable means for eflecting relative movementbetween the supports, of a pivotally mounted tracer on one of saidsupports deflectible to control the flow of fluid pressure to said fluidoperable means, means for controlling the amount of tracer deflectionand thereby the rate of relative movement between the support includinga sleeve co-axial of the tracer and having a tapered portion, thesupport for the tracer having a bore formed therein for receiving saidtapered portion, and means threaded on the tracer for adjusting saidsleeve to produce a predetermined clearance between the tapered portionand the bore to determine the amount of tracer deflection and therebythe rate of said relative movement.

10. In a milling machine having a work support and a tool support, thecombination with fluid operable means for eflecting relative movementbetween the supports, of a pivotally mounted tracer on one of saidsupports deflectible to control the flow oi fluid pressure to said fluidoperable means, means for controlling the amount of tracer deflectionand thereby the rate 01 relative movement between th supports includinga sleeve co-axial oi. the tracer and having a tapered portion, thesupport for the tracer having a bore formed therein for receiving saidtapered portion, means threaded on the tracer for adlusting said sleeveto produce a predetermined clearance between the tapered portion and thebore to determine the maximum amount oi. pressure deflection and therebythe rate of said relative movement, and manual means operable at will toeflfect a further shifting of said sleeve to effect a rapid traversemovement between said supports.

11. In a pattern controlled machine tool having a work support and atool support, the combination with fluid operable means tor eflectingrelative movement between the supports, of a deflectible tracer, theamount oi deflection of said tracer controlling the rate of fluid flowto said fluid operable means and thereby the rate of said movement,means for controlling the amount or tracer deflection including a sleeveco-axial with the tracer, said sleeve having an external tapercooperating with a bore formed in the tracer support, positivelypositionable means carried by the tracer for shifting said sleeve fordetermining the amount of clearance between said tapered portion andsaid bore, and resiliently operable means for deflecting the tracer theamount of said clearance.

12. In a pattern controlled machine tool having a work support and atool support, the combination with fluid operable means for eflectingrelative movement between the supports, 01' a deflectible tracer, theamount or deflection of said tracer controlling the rate of fluid flowto said fluid operable means and thereby the rate of said movement,means for controlling the amount 01 tracer deflection including a sleevemounted on the tracer, said sleeve having an external taper cooperatingwith a bore formed in the tracer support, positively positionable meanlcarried by the tracer for shifting said sleeve for determining theamount of clearance between said tapered portion and said bore,resiliently operable means for deflecting the tracer the amount of saidclearance to produce relative movement between the cutter and work ata'predetermined rate, and independently operable means for controllingthe movement of the cutter toward and fromlthe work during said relativemovement.

13. In a mechanism for removing material to form a work cavity inaccordance with a pattern, the combination of a work support, a toolsupport, manually operable means to feed the tool support toward thework support, power operable means for eiiecting relative movementbetween the supports, a tracer control mechanism for said power operablemeans, a masking bar adapted to be superimposed over the pattern, meansto support the bar for lateral indexing, means to urge the tracer intoengagement with said bar to eifect operation of said power operablemeans, and means to index the bar and change the angle of urge on thetracer to reverse the direction or movement between said supports.

14. In a pattern controlled machine tool having a power operable toolsupport and a'power operable work support mounted for three-directionalrelative movement, the combination of control means therefor including afirst tracer controlled mechanism for governing two directional relativemovement between said supports and a second tracer control mechanism forgoverning the direction of relative movement in the third direction.

'15. In a pattern controlled machine tool having a work support and atool support, the combination of power operable means for effectingrelative movement between the supports, of control means thereforincluding a universally deflectible tracer, the plane of deflection ofwhich determines the direction of relative movement between the supportsand the amount of deflection determining the rate of said movement, ratedetermining means adapted to be set to limit the amount of tracerdeflection, means to determine the direction of tracer deflection, andindependently operable means to increase the limit of tracer deflectionwithout eflecting said rate determining means to produce a rapidtraverse movement between the slides.

16. In a pattern controlled machine tool having a tool support and awork support, one of which is adapted to serve as a tracer support andthe other as a pattern support, the combination of control means forgoverning relative movement between the supports in a plurality ofdirections including a tracer pivotally connected at one end to thetracer support, an indexible ring mounted on the tracer supportintermediate the ends of the tracer and surrounding the same, a tracerdeflecting plunger mounted on the ring for axial movement perpendicularto the tracer axis, means for indexing the ring to a limited number ofpositions throughout 360 degrees to change the plane of movement of saidplunger, and means for imparting a limited circumferential movement ofthe plunger about the tracer and relative to said ring to obtain minutevariations in the position of the plunger.

17. In a. pattern controlled machine tool having a cutter support and awork support and power operable means for effecting relative movementbetween the supports, the combination of control means for said poweroperable means including a tracer mounted on one of said supports forcooperation with a pattern mounted on the other support, said tracerbeing pivotally connected at one end to its support for universallateral oscillation, means intermediate the ends of the tracerforimparting a limited lateral deflection to the tracer, means responsiveto any deflection of the tracer for causing relative movement betweenthe supports, means for rotatably positioning the tracer deflectingmeans about the tracer for determining the radial plane of deflectionthereof, and means responsive to the plane of tracer deflection fordetermining the direction of relative movement'between the supports. a

18. In a pattern controlled machine tool having a cutter support and awork support and power operable means for effecting relative movementbetween the supports, the combination of control means for said poweroperable means inperpendicular to the tracer to effect deflectionthereof when said first-named means are released, means to orient theplunger about the tracer to cause the plane of deflection thereof tointersect the periphery of the pattern, and means to render said plungerineffective whereby the tracer may be manually controlled.

19. In a milling machine having a tool support and a work supportmounted for three-directional relative movement, the combination ofseparate power operable means for eflecting each of said movements, amanually operabletracer supported for universal movement in a plane,means operatively connected to the tracer for controlling operation oftwo of said power operable means and thereby universal relative movementbetween the tool and work in said plane, an automatically operabletracer supported for engagement with a separate pattern, means couplingthe tracer for automatic control of the third power operable meanswhereby during manually controlled tracing in the first plane relativemovement between the tool and work perpendicular to said plane will beautomatically controlled by said second tracer.

} 20. In a die-sinking machine having a tool 10 holder and a work holdersupported for relative movement in three directions and separate poweroperable means for efiecting movement in the respective directions, thecombination of c011 trol m'eans therefor including a first tracer mech-5 anism operatively connected for joint or several control of a pair ofsaid fluid operable means whereby universal movement between the tooland work in a given plane may be eflfected in accordance with theoutline of a pattern lying in said plane, a second tracer coupled forautomatic control of the third power operable means, means normallydisconnecting the second tracer from the third power operable means,said second tracer being adapted to cooperate with 5 a second patternoutlined to control movement between the tool and work in a directionperpendicular to said plane, manually operable means for controllingsaid third power operable means and thus relative movement between thetool and workin a direction to eflect engagement of said second tracerwith its cooperating pattern, and means responsive to engagement of thesecond tracer with its pattern for effecting automatic connection of thesecond tracer with said third power operable means whereby movementsbetween the tool and work in a direction perpendicular to said plane maybe automatically controlled during manual manipulation of the firstnamedtracer in controlling relative movement between the tool and work insaid plane.

21. In a die-sinking machine for forming cavities in a die block, thecombination of a tool support and a work support for holding said dieblock, the combination of means mounted -on said work support forsupporting a first pattern having a profile corresponding to the outlineof said cavity in a cross sectional plane and a second pattern shaped toconform to the contour of the bottom of said cavity, a manually operabletracer supported for engagement with the first pattern, power operablemeans controlled thereby for goveming universal movement between thetool and work support in the plane of said pattern, a second tracercooperating with the second pattern, power operable means controlledthereby for governing movement between the tool and work support in adepthwise direction, manually operable means for controlling relativeadjustment to eflect engagement of the second tracer with its pattern,and means responsive to said engagement for automatically coupling thesecond tracer for control of its power operable means whereby duringmanual manipulation o the first tracer the seconiitracer will automatically control movement between the tool an work in a third direction.

ERWIN G. ROEHIVI.

